Amit Kapila <amit.kapila@huawei.com> writes:
> I want to clarify small doubt in this regard.
> In function make_rels_by_clause_joins(..), it tries to join the given
> relation old_rel with other relations if there exist a join between them.
> What I can understand is, it is because if there exists a join condition its
> better to join with that relation.
> However if the given relation old_rel is not able to join any relation, then
> why can't it try to make cross-join with other relations there itself.
Hm? That case is handled by make_rels_by_clauseless_joins. I suppose
we could refactor to combine those two functions, but what's the point?
If that's not what your question is about, then I don't understand.
regards, tom lane